1. Field of the Invention
The present invention relates to a one-piece foamer nozzle which is moveable between an "OFF" position and a "FOAM" position and which is mounted on the front end of a trigger sprayer.
2. Description Of The Related Art Including Information Disclosed Under 37 CFR .sctn..sctn.1.97-1.99
Heretofore various foam dispensing devices have been proposed which are mountable on a trigger sprayer. Such devices include nozzle assemblies which are mountable at the front end of the trigger sprayer. All these devices include a foam generating chamber, means for admitting air into the 15 chamber, and an outlet from the chamber. In some of these devices a screen is provided for assisting in the generation of foam.
A trigger operated foam dispensing device which utilizes a foam generating chamber and a perforated wall through which foam is ejected is disclosed in the Tada U.S. Pat. No. 4,350,298. In this patent, the trigger operated foam dispensing device includes a nozzle cap with an outlet wall having a plurality of arms constituting an obstacle wall against which liquid from a spray or stream outlet orifice collides, thereby to mix with air in the nozzle cap to form foam which exits the nozzle cap through three or more openings formed between the arms of the outlet wall.
A two position foam nozzle assembly for use with a trigger sprayer is disclosed in Japanese Patent Publication No. 133358/1981.
Another two-position nozzle assembly having an "OFF" position and a "FOAM" generating position established by rotation of the nozzle assembly about a nozzle bushing is disclosed in the Maas U.S. Pat. No. 4,730,775, entitled TWO-PIECE FOAMER NOZZLE ASSEMBLY. In this patent, a foam generating chamber is provided that is positioned forwardly of an orifice within the nozzle assembly and foam created in the foam generating chamber passes into a foam accumulating chamber, the two chambers being separated by three spokes or a Y formation.
Japanese Patent Publication 63-51670, published in 1988, discloses a foam nozzle assembly wherein a foam generating chamber is positioned in front of an orifice within the inside of the nozzle assembly and foam exits directly from the foam generating chamber.
In the Shay et al U.S. Pat. No. 4,767,060 there is disclosed a nozzle which is capable of selectively dispensing a liquid product as a foam or a spray. In this nozzle, an annular foamer member is moveable axially of the nozzle axis from a position adjacent an outlet orifice in the nozzle body to a position spaced forwardly of the nozzle orifice where the spray from the nozzle orifice can engage an inside surface of a sleeve of the foamer member for making foam.
In the Shay U.S. Pat. No. 4,768,717 there is disclosed a nozzle including a cylinder defining a foam generating chamber. An orifice is located in the nozzle at the entrance end of the foam generating chamber. One or more air passageways within the nozzle allow air to enter into the entrance end of the foam generating chamber. A spray of liquid from the orifice into a foam generating chamber mixes with the air entering from both axial ends of the cylindrical foam generating chamber to form foam.
The Corsette U.S. Pat. No. 4,779,803 discloses a manually actuated liquid sprayer which is adapted to generate foam when a ported movable element is moved to an axially extended position. The element has a central cylindrical port therein larger than an outlet orifice positioned behind the element. Liquid sprayed from the orifice engages the cylindrical wall of the central port to create foam when the element is extended.
A trigger sprayer nozzle having an outer shape similar to the shape of the one piece foamer nozzle of the present invention is illustrated in the Verhees U.S. Pat. No. 293,929.
As will be described in greater detail hereinafter, the one-piece foamer nozzle of the present invention differs from the previously proposed foamer nozzle assemblies and, in particular, from the one-piece foamer nozzle illustrated in U.S. Pat. No. 293,929 by providing, in addition to an outer barrel portion in the nozzle which forms a foam generating chamber, an annular formation extending a short distance forwardly from a wall within the outer barrel portion which has an orifice from which liquid is sprayed in a conical spray into and against the inner surface of the outer barrel portion forming the foam generating chamber. It has been discovered that this short annular formation increases, enhances or facilitates the generation of foam, as a result of some of the conical spray from the outlet orifice in the nozzle hitting the inner surface of the short annular formation and causing greater turbulence in the outer barrel portion. In this respect, the portion of the conical spray that impinges upon the inner surface of the short annular portion will be deflected into the rest of the conical spray that passes out of the short annular portion to impinge upon the inner surface of the outer barrel portion, thereby, increasing the cross flow and turbulence of liquid and air in the foam generating chamber to create foam.